Apparatus for heat-treating propellers and the like



jan. 3, W5@ F. A. @RUE-MEN Filed Dec.

6 Sheets-Sheet l INVENTOR.

frederick A Gruezy'en ATTQRNEY jm.. 3, w50 F. A. GRUETJEN APPARATUS FOR HEAT-TREATING PROPELLERS AND THE LIKE' e sheets-sheet 2 Filed Dec. 21,l 194.3

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TTORNEY.

jam. 3 M50 F. A. GRUETJEN 29493935 APPARATUS Foa HEAT-TREATING PROPELLERS AND THE LIKE Filed Dec. 2l, 1945 6 Sheets--Sheel 5 Fre derck A. Gruej'e INVENTOR ATTORNEY im., 3, W5@ F. A. @RUETJEM 29335 APPARATUS FOR HEAT-TREATING PROPELLERS AND THE LIKE Filed Dec. 21, 1943 6 Sheeis-Sheel 4 Frederick AG1/negen INVENTOR.

TTURNEY 5m., E, m5@ F. A. GRUETJEN 29493335 APPARATUS FOR HEAT-TREATING PROPELLERS AND THE LIKE 5 Sheets-Sheet 5 Filed Dec. 2l, 1943 2, f U Z t-- lrz a wa y Q @W k m j E l] F f/|% 9 A@ Q :3

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INVENTOR.

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ATTORNEY VL B APPARATUS FOR HEAT-TREATING PROPELLERS AND THE LIKE 3 3 E195@ F. A. GRUETJEN 6 Sheets-Sheet 6 Filed Dec.

Frederzkk @rmi/'m INVENTOR.

` /fj- "i J ATTORNEY Patented Jan. 3, 1950 APPARATUS FOB HEAT-TREATING PROPELLERS AND THE LIKE Frederick A. Gruetjen, Milwaukee, Wis., assignor to A. 0. Smith Corporation, Milwaukee, Wil., a

corporation oi' New York Application December 21, 1943, Serial No. 515,113

.treating propeller blades and the like, and provides an apparatus which is less costly and more eilicient for the purpose.

One of the objects of the invention is to avoid the difficulties encountered in prior practice of supporting the heated blade in a horizontal position as it is placed in the dies of a press for forming and quenching the same.

Another object of the invention is to avoid the requirement of an expensive press of large size and great power in conning the propeller blade during quenching.

A more specific object of the invention is to provide an apparatus for quickly removing a propeller blade from a heating furnace, conveying it to a quenching die and supporting the same during operation of the latter.

Another object is to provide a simple and inexpensive mechanism for operating and locking the quenching dies.

Another object is to provide an apparatus in 12 Claims. (Cl. 266-2) which the propeller blade is suspended vertically throughout its heating and quenching operation.

Another object is to provide a simple indexing and operating mechanism for accurately locating the propeller blade in the dies.

Another object is to provide for the use of a number of individual furnaces with a single quenching apparatus to compensate for the different time rates vfor heating and cooling and avoid the difficulties inherent in employing a single large furnace unit.

Other objects will appear hereinafter in connection with thevdescription of the embodiment of the invention illustrated in the accompanying drawings.

In the drawings:l v

Figure 1 is a side elevation of the apparatus with parts sectioned and showing a propeller blade in the furnace;

. Fig. 2 is a front elevation of the quenching'de vice with parts sectioned to show the toggle operation;

Fig. 3 is a top plan view of the apparatus;

Fig. 4 is a transverse horizontal section through the carriage;

Fig. 5 is a longitudinal section taken on line 5-5 of Fig. 4;

Fig. 6 is a transverse vertical section taken on line 8 5 of Fig. 5 and mechanism;

Fig. 'I is a transverse section through the quenching dies taken on line 'I-l of Fig. 2;

2 Fig. 8 is a detail front elevation of the left-hand die;

Fig. 9 is a detail front elevation of the face of the right-hand die;

Fig. 10 is a transverse section through the dies taken on line I0-I0 of Fig. 2 and showing the connections for cooling the blade shank;

Fig. 11 is an enlarged detail view partially in section showing the universal joint for suspending the propeller blade;

Fig. 12 is a control diagram showing a semiautomatic control for the apparatus; and

Fig. 13 is a schematic showing of a factory installation of a plurality of furnaces and a quenching device.

The apparatus is employed to heat a welded low alloy high strength hollow steel blade of substantially the finished shape, and then to quench the blade while holding it in shape. For this purpose, instead of directing afquenching uid onto the surface of the blade, the latter is. confined in substantially uniform contact with dies of high heat conductivity and through which a cooling medium is circulated. For the purpose .0f providing a uniform contact between the surface of the blade and the dies, a fluid pressure is applied internally of the hollow blade.

'I'he apparatus comprises in general a heating furnace I, a quenching device 2, and a conveyor mechanism 3.

The furnace I is preferably of the electric resistance type and is disposed like a well in the floor 4 of the shop with an opening 5 in its top for passage of the blade into and out of the furnace. Suitable heating elements 6 line the wall of the furnace and are connected through a transformer 'l to a source 8 of electric heating the face of -i energy.

frame 9 of generally horseshoe section having an showing the indexing opening I0 in the side facing the furnace for receiving a blade II by lateral movement of the latter. Theframe 9 has a fixed die I2 with a recessed face I3 for receiving and confining one side of the twisted blade, and a movable die I4 lwith a similar complementary recessed face I5 for receiving and confining the other side of the twisted blade. The dies I2 and Il are removable to provide for ready replacement with dies for diierent sizes and shapesof blades. v

The die I4 is moved toward and away from the die I2 by means of a plurality of toggles I6 ar-` ranged parallel to one another and distributed one above the other at suitable spaced intervals in the height of the die. For a die accommodating a blade of about six feet in length. the apparatus illustrated has ve toggles Ii, each having two links I l and Il. pivoted to a common central toggle pin I9. The outer ends of the links I8 are pivoted to a set of fixed pins 20 secured in the frame l. The outer ends of links I'I are pivoted to a set of pins 2I secured to the moving die backing or support. 22.

The support 22 and its die I4 are mounted for movement toward and away from the die I2 in frame 9 which has slide plates 23 at the top and Y bottom for holding the dies in proper relative alignment.

'lhe central toggle pins I9 pass through a pair of vertical toggle connecting arms 24 which secure the toggles together for simultaneous operation and serve to raise and lower the toggle pins I8 to operate the toggles. 'lhe arms 24 extend upwardly through the top of the frame and are connected by a pivot pin 25 to the short arm of a pivoted operating lever 26.

The lever 26 comprises two parallel bars pivoted on a fulcrum bracket 2l on top oi the frame, and the long arm of the lever is connected at its outer end to a piston rod 28 oi' power cylinder 29 which is pivotally mounted on a bracket 3U on the side of the frame 9. A suitable adJustable stop 3i on frame 9 determines the limit of movement of lever 26 in spreading the toggles and closing the dies. This adjustment should allow the toggles to pass dead center when the lever engages tne stop to provide a lock for the toggles and prevent possible opening of the dies during quenching.

'lhe frame 9 is reinforced by a plurality of horizontal plate ribs 32 embracing the frame around the back side and either welded thereto or cast integrally therewith. The frame has a top plate 33 which additionally secures the parts of the frame against deflection, the plate 33 having only the requisite slot 34 for receiving the support rod for the propeller blade II. The base 35 of the frame extends across the opening I0 and secures the two sides of the frame directly together at the bottom. Heavy upright plates 36 are secured to top plate 33 and base 35 on opposite sides of the opening I0, and to the frame 9 for preventing deilection of the latter at intermediate points and to confine the dies.

The dies I2 and I4 have a series of ducts 31 distributed uniformly at a predetermined depth from the faces I3 and I5 for the purpose of transferring heat rapidly from the blade ing uid such as water flowing through the ducts. Suitable pipe connections 38 are made to circulate water through the ducts 31.

The conveyor mechanism 3 comprises a pair of parallel horizontal spaced channel tracks 39 supported on top of the frame 9 and extending out over the furnace I. A carriage 40 is supported by four rollers 4I riding in the channels 39 and is adapted to reciprocate between a position directly over the opening in the furnace and a position directly over the recessed faces of dies I2 and I4 to transfer successive blades from the furnace to the quenching dies.

The carriage 4II is normally held in a position over the furnace opening 5 by means of a pair of cables 42 which are secured at one end to upstanding lugs 43 on top of the carriage, and pass in a reverse bend over xed pulleys 44 on a cross member 45 at the forward end of the track 39, then through holes 46 in the carriage to the rear end of the track 39 and down over a pair of fixed pulleys 41 to a weight 4l. The weight 43 is sumciently heavy to hold the carriage in place at the forward end of the track during lowering and raising of a propeller blade into and out of the furnace.

The carriage 40 has a rectangular pan-like frame, and the rollers 4I are secured to end extensions of the side members of the frame. Reinforcing pads 49 are laid in the bottom of each corner of the frame and an index pin 50 is suspended for vertical movement through the same from a similar pad 5I disposed at the top of each corner of the frame.

The propeller blade' II is suspended tip-down from an elevator 52 which may have secured thereto a cover 53 for the furnace opening 5 and a suitable pipe connection 54 for supplying nitrogen or other suitable gas under pressure to the inside of the blade. A vent 55 provides for a measured escape of gas from the blade in purging the latter of oxygen.

The elevator 52 has a stem 56 extending downwardly and threaded into the shank of the blade to suspend the same during heating in the furnace. The stem 55 has a nange 51 at its upper end with a tapered lower surface adapted to rest upon a laterally movable sealing ring 58 supported in a cup 59 at the top of the elevator. This constitutes a universal joint which allows the blade I I to hang vertical regardless of the fact that the elevator may not be vertical or of possible distortion of the same. At the same time, it allows for lateral movement of the stem in response to tolerances involved in positioning the blade in the dies.

The top of the elevator 52 is rectangular, and it has an index plug 60 with a tapered index hole for receiving the corresponding conical lower end of the respective index pin 50 at each corner when the elevator is raised to its upper position beneath the carriage 40.

Raising and lowering of the elevator 52 is accomplished by a pair of chains 6I, each having one end removably secured to threaded lugs 62 in the top of elevator 52 and the other end se- II to a coolthe dies, the blade is withdrawn by raising cured to a cross member 63 at the rear end of the track 39. The chains 6I pass over sprockets 64 rotatably mounted on a. bar 65 supported transversely between upstanding ears 66 on the sides of the carriage frame. The chains 6I pass horizontally from sprockets 64 to a series of sprockets 51 at the rear end of track 39. The

sprockets 61 are arranged with two pair of xed' sprockets and two pair of movable sprockets, somewhat similar to block and tackle systems.

" The movable sprockets are secured to a header 53 on the upper end of the piston rod 69 of power cylinder 'IIL By utilizing the sprocket arrangement illustrated, the stroke of the piston in the cylinder 'I0 is only a fraction of the resulting vertical movement of elevator 52.

In operation. a downward movement of the piston rod 69 raises the elevator 52 from its lower position, where the blade II is being heated in the furnace, to its upper indexed position beneath carriage 40 where the blade Il is entirely out of the furnace. vFurther downward movement of the piston rod 69 results in pulling the carriage 45 to the rear along track 39 and against the pull of cables 42 raising the weight 48 until the carriage engages a pair of adjustable stops 1I adjacent track 39 to stop the carriage when the blade Il is centered relative to the dies I2 and I4. After quenching of the blade II in piston rod 88 and allowing weight 48 to pull the carriage forward to its normal position. The blade can then be removed and a succeeding blade secured to the lower end of stem 56 and lowered into the furnace for heating.

In order to prevent one side of the propeller blade from 'engaging one of the dies prior to the other side engaging the other die, and consequent warpage of the blade with uneven heat treatment thereof, the elevator 52 has the pipe connection 54 and upper end of stem 56 secured in a transversely movable platform 12 slldably supported on two'transverse rods 13 secured in the side plates of the elevator top. A central guide rod 14 carries a coil spring 15 which normally biases the platform 12 to one side of the elevator top. 'I'he platform 12 has a projection 16 extending through the side of the elevator and which is engaged by a push rod 11 during movement of die |4 to move the platform laterally with the die.

The movement of the platform 12 is approximately one-half that of the die I4 so that the blade will be disposed about midway between the dies at all times during the die closing movement. For this purpose push rod 11 is operated by a toggle 18 having its center pin 18 connected to the lever 26 by a link 88. Operation of lever 26 in closing and opening the dies simultaneously operates the sliding of platform 12 in the elevator top.

The blade is accurately located in the dies by a camming action provided by the curvature of the shank 8| of the blade, the curvature of the tip index projection 82 of the blade and by cam blocks 83 disposed on opposite sides of die l2 about midway in the height of the die and entering corresponding recesses 84in the die I4. As the dies close upon the blade this cam action brings the blade into proper alignment with the die faces in the event there is any distortion of the blade from normal dimensions and shape or that the blade is not hanging truly vertical.

The proper quenching of the thick shank 8| is more diicult than that of the thin air foil section of the blade since the internal gas pressure is not elective to press the walls of the shank outwardly into tight contact with the dies. This is partially compensated for by employing a cushioned die insert 85 in each of the dies for engaging the shank on one side. The die inserts 85 are pressed outwardly by compressible rubber 86 or other suitable material disposed between the back of the inserts and the dies I2 and |4. When the inserts 85 engage the shank 8| of the blade during closing of the dies, the rubber 86 is compressed until the dies are completely closed, thereby providing a tight; contact between the inserts and the shank.

The inserts 85 are preferably of copper and have grooved semi-cylindrical faces for receiving the shank.

The grooves 81 in the faces of the insert are interconnected and joined to a header 88 having a pipe connection 88 for supplying a cooling spray of water and air to the surface of the shank. In practice the actual rate of cooling of the shank end of the blade should be a little slower than that of the tip end.

The hydraulic control circuit illustrated in the diagram of Fig. 12 shows the manner of operating the apparatus. The power circuit for supplying uid pressure to the power cylinders 28 and 18 includes a pump 88 and a iluid pressure I tank or accumulator y The supply line 82 has branches 84 and 85 lead- I 8| with a supply line 82 for cylinder 28 and a supply line 83 for cylinder 18.

ing to the opposite ends of cylinder 28 with a multiple control valve 86 at their juncture for alternatively supplying nuld from pipe 82 to either end of the cylinder and simultaneously exhausting lluid from the opposite end of the cylinder. The supply line 83 has a three-way valve 81 alternatively supplying fluid to cylinder 18 or exhausting fiuid therefrom.

The gas supply circuit for the blade comprises a high pressure gas bottle 88 containing nitrogen or other suitable inert gas at a high pressure (normally around 2000 lbs. per sq. in.) and an auxiliary gas bottle 88 for receiving and storing a quantity of gas at the (normally around 300 lbs. vper sq. in.) A pressure reducing valve |88 automatically feeds gas from bottle 88 to bottle 88 to maintain the required operating pressure in the latter.

A pipe line |8| leads branch lines |82 and |83. Branch line |82 contains a reducing valve |84 which supplies a very v small flow of gas to the blade through pipe 54 during heating, the pressure of the gas in the blade being limited to only one or two pounds per square inch. Branch line |83 bypasses the valve |84 and contains a compressed air operated quick opening valve |85 to supply the fullgas pressure in bottle 88 to ythe blade when the latter is confined inthe quenching dies.

The water circulation for cooling the dies is obtained from accumulator 8| through pipe 38 to the ducts 31 in the respective dies, one of the pipe connections being flexible to provide for relative movement between the dies.

The water spray for the shank is provided by pipe connections 88 from a spray-mix chamber |86 to the respective headers 88, one of the counections 88 being iexible to provide for relative movementbetween the inserts 85. The mixing chamber |85in turn receives its air through check valve |81, manual pressure regulating valve |88 and control valve |88, from the air supply line I8 normally supplying air at about one hundred pounds per square inch pressure. The chamber |86 receives its water through' a normally closed diaphragm control valve from lthe water storage tank ||2, the latter being supplied through a check valve I3 from the ordinary tap water supply line H4.

The filling of tank ||2 is escape of air from the top of a controlled by the lloat control chamber ||5 through the normally open diaphragmv control exhaust valve ||6, the oat ||1 serving to cut oft further escape of water through the valve ||6.

The operation of the spray is eected bythe opening of control valve |89 by the operationof the die closing lever 26, admitting air under pressure to the mix chamber |86, as previously described. Air also passes from valve |88 through a check valve ||8 to the top of float chamber ||5 to force the water out of tank ||2 into the mix chamber |88. For this purpose air pressure from valve |88 is admitted to valve to open the same, and also to exhaust valve Al l5 to close the same.

An interlock may be control .valve |88 and valve |85 to open the latter at the time the dies are closed. .y

When the blade is quenched, the valve |85 is closed and valve 55 opened to release the internal nitrogen pressure, from the blade. Then the required operating pressurefrom bottle 88 to twoV provided between thev ananas i 7 wntroi valve is closed. thereby stopping the spray of water on the shank and closing valve and opening valve II6.

If desired, an additional air blast may be applied to the stem 56 to rapidlycool the same and prevent its retained heat from effecting the quench of the upper end of the blade shank. This may be done by a branch pipe |I'9 leading from the line between pressure regulating valve |08 and check valve |01 to a stem spray nozzle |20.

The cycle of operation is substantially as follows:

The cycle starts with the blade in furnace I where valve |04 feeds inert gas from bottle 08 slowly to the inside of the blade, allowing the gas to leak out of the vent valve 55 at the upper end of the blade supporting stem 56. The nitrogen in the blade during heating prevents oxidation of the metal inside.

When the blade II is heated to the required temperature for quenching, valve 91 is opened admitting power fluid from the accumulator tank .9| through line 93 to cylinder 10, thereby pulling piston rod 69 and header 68 downwardly and raising the elevator 52 until it indexes with carriage gli. Thereafter the downward movement of piston rod 69 is continued to pull the carriage 40,

elevator 52 and blade horizontally along track e 80 until carriage 40 engages stops 1|, indicating that the blade is centered between the dies I2 and I4. The weight 48 raises during the above described horizontal movement of carriage 40.

When the blade is centered between dies |2 and I4, valve 96 is turned to admit power uid from tank 8| to the upper end of cylinder 29 and to simultaneously exhaust fluid from the lower end of the cylinder to thereby operate the toggles I0 to move die I4 against die |2 and thereby confine the blade between the closed dies. During this closing of the dies, the push rod 11 operated by toggle 18 from lever 26 pushes the platform 12 transversely on the carriage at a rate approximating one-half the rate of movement of die I4 to maintain the blade midway between the dies at all times and prevent early contact of only a portion of the blade. During the final stage of the after which valves |06 and die closing operation, the blade is cammed into y the recesses in the die faces I3 and I5 by means of the cam blocks 83 engaging the edges of the blade, the action of the inserts 85 upon the shank,

and the action of the die faces on the tip4 index After the toggles I6 pass dead center. the stop 8| is engaged by the lever arm 26 to prevent further operation of the toggles, and the control valve |09 is automatically opened. The valve |05 in branch line |08 is opened wide to quickly admit the full pressure of the gas in bottle 99 to the inside of blade I I and press the sides of the blade outwardly against the confining die surfaces.

At the same time air passes from control' valve |09 through valves |08 and |01 to mix chamber |08. Air also passes from control valve |09 directly to the valves and IIB, opening the former and closing the latter. In addition to this, air passes from control valve |09 through check valve ||8 to the top of the chamber ||5, thereby forcing the water from chamber I I5 and tankl I2 into the mix chamber |06. The air and water in mix chamber |06 is forced through connectlon 0l to the header 88 in inserts 85 where the mixture is sprayed onto the shank of the blade.

During theclosing of the dies and preferably prior to n'al closing. water is admitted from ac- 8 cumulator 9| through pipe 08 to the ducts 81 in the respective dies, and a continuous flow of water is maintained through the ducts during cooling of the blade.

The blade is ordinarily left in the dies for about five minutes, until a proper quench is assured, |09 are shut and the gas pressure is released from the inside of the blade by the manual bleeder valve 55. Valve 96 is then turned to admit power fluid from tank 9| to the lower end of cylinder 29 and to simultaneously exhaust fluid from the upper end of the cylinder, to thereby operate the toggles I6 in a direction effecting opening of the dies. During this opening movement, the rod 11 will be gradually retracted by toggle 18, allowing the spring 15 to return the platform 12 to normal conveyor position with the blade spaced midway between the open dies.

After separation of the dies, valve 91 is operated to allow a limited upward movement of piston rod 69 and header 68, effected by weight 48 pulling the carriage 40 forward on track 89. The forward movement of carriage 40 brings the blade out of the quenching apparatus 2 to a position where it can be readily removed from stem 56 and a new blade secured in place for lowering into the furnace. q

The control above described is largely semiautomatc. The amount of manual control and of interlockof the several operations is purely a matter of choice.

In actual practice, the quenching apparatus 2 and its conveyor mechanism 3 are mounted on a track |2| extending adjacent to aline of furnaces I, as illustrated in Fig. 13. In this way a single quenching apparatus can handle the output of six or seven furnaces, 'and by reason of its equal proximity to each furnace when in operation, the quenching of the blades from successive furnaces will be substantially equal and uniform. The time cycle of operation of the quenching apparatus is only a small part of the time cycle for Vheating a blade in a furnace. The quenching apparatus 2 can be moved from one furnace to another and be kept in operation almost constantly. By employing a plurality of small individual furnaces instead of a single large one, the production line can be kept in operation during times when a furnace is shut down for repairs or for other reasons.

The invention may have various embodiments within the scope of the accompanying claims.

I claim: Y 1. In an apparatus for treating propeller blades and the like, a quenching device comprising vertically disposed relatively laterally movable quenching dies having complementary die faces for receiving and confining a blade, means automatically adjustable laterally in correlation to the closing of the dies upon the blade for suspending a blade therein, means for closing said dies upon the blade, and cam means for straightening said blade relative to said die faces as the latter close upon the same.

2. In an apparatus for treating propeller blades i and the like, a quenching device comprising a vertically disposed fixed die member, a vertically disposed laterally movable die member, said die members having complemental faces for receiving a blade suspended therebetween. a carriage for transferring a blade to said dies, a platform in said carriage for carrying the blade, and

means providing limited transverse movement of 9 said platform relative to said carriage to position the blade accurately in said dies.

3. In an apparatus of the class described, a carriage for transferring a blade horizontally from one position of treatment to another, an elevator suspended from said carriage for raising and lowering the blade, means for indexing said elevator with said carriage when said elevator is in uppermost position, a platformin said elevator for carrying the blade, and means providing limited transverse movement of said platform relative to said elevator and carriage to position the blade accurately in a vertical `direction and in two horizontal directions. Y

4. In an apparatus of the class described, a hollow vertical stem for securing they shank of a propeller blade and the like to suspend the same, said'stem having a flanged head adapted to rest on a horizontally movable ring to support f the head in a laterally floating manner for die quenching metal articles.

5. In an apparatus of the class described, a quenching die for receiving a hollow heated article made up in part of rigid walls and in part of flexible walls, a cushioned die insert for receiving the rigid walls of the article, and means for pressing the flexible walls of the article against the face of the die to provide a uniform heat conductive contact between the article and die to effect quenching of the article.

6. In an apparatus for treating propeller blades and the like, a quenching device comprising vertically disposed relatively laterally movable dies having complementary die faces for receiving and confining a blade, means for suspending a blade therein, and means for closing said dies upon the blade, said suspending means comprising a hollow vertical stem for securing the shank of the blade and having a flanged head adapted t rest on a horizontally movable ring to support the head in a laterallyV floating manner for centering the same in the quenching dies.

A'1. In an apparatus for treating propeller bladesl and the like, a quenching device comprising vertically disposed relatively laterally movable dies having quenching die faces for receiving and confining a blade in direct contact conducive of uniform conduction of heat from substantially the entire surface area of the blade for quenching the same, and means' including a slidable carriage disposed above the dies and automatically adposed above the dies vto suspend a blade between the open die faces including a slidable carriage automatically adjustable laterally with respect to the path of travel of the carriage in synchronism with the closing of the dies upon the blade, and means disposed to operate said movable die member to open and close said dies including means to simultaneously move said slidable carriage a predetermined distance in` relation to the travel of said movable die.

10. In an apparatus for treating propeller blades and the like, a quenching device comprising a vertically disposed fixed die member, a verjustable laterally with respect to the path of travel of the carriage in synchronism with the closing of the dies upon the blade for suspending a blade between the dies.

l8. In an apparatus for treating propeller blades and the like, a quenching device comprising vertically disposed relatively laterally movable dies having complementary die faces for receiving and confining a blade, a slidable carriage disposed above said dies and automatically adjustable laterally with respect to the path of travel ofthe carriage in synchronism with .the closing of the dies upon the blade for suspending a blade -between the dies, and means disposed to close the dies upon the blade including means to move said slidable carriage a predetermined distance in relation to the travel of the dies.

9. In an apparatus for treating propeller blades and the like, a quenching device comprising a vertically disposed fixed die member, a vertically disposed die member laterally movable toward and away from said fixed die member, said die members having complemental faces for receiving a blade suspended therebetween, means distically disposed die member laterally movable toward and away from said fixed die member, said die members having complemental faces for receiving a blade suspended therebetween', means disposed above the dies to suspend a bladebetween the open die faces including a slidable carriage automatically adjustable laterally with respect to path 'of travel of the carriage in synchronism with the closing of the dies upon the blade, means disposed to operate said movable die member to open and close said die,`and means operatively connected to said die moving means to simultaneously move said slidable carriage a predetermined distance to prevent contact of the blade with either face until final closing position.

11. A quenching device for treating propeller blades and the like, comprising a rigid upstanding frame of substantially horse-shoe shape having a vertically disposed opening through one side thereof, a vertically disposed fixed die member at one side of said opening and a vertically disposed die member at the other side of said opening and laterally movable toward and away from said fixed die member within said frame, said die members having complemental faces for receiving a blade suspended therebetween, a series of toggles disposed between and, pivotally secured to said movable die member and saidframe and spaced apart and distributed vertically behind said die member, and means disposed to operate said toggles simultaneously to pen and close said dies.

12. A quenching device for treating propeller blades and the like, comprising a rigid upstanding frame of substantially horse-shoe shape and having a vertically disposed opening through one side thereof for receiving work to be quenched, a plurality of vertically distributed horizontally extending reinforcing ribs embracing a major portion of said frame to secure the latter against deflection, a vertically disposed fixed die member and a similarly disposed laterally movable die member within said frame and having complemental faces for receiving a blade suspended therebetween, a series of toggles disposed between and pivotally secured to said movable die member and said frame, said toggles being spaced apart and distributed vertically behind said die member, and means for operating said toggles to open and close said dies.

FREDERICK A. GRUE'IJEN.

REFEREN CES CITED Th'el following references are of record in the file of this patent:

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